The present invention pertains to a color sensor solution used to identify the type of ribbon loaded in a printer by using a plurality of colored marks applied to the ribbon""s core.
After the colored marks are detected, the printer automatically receives and sets the parameters to operate the printer using the particular type of ribbon detected.
The instant invention also protects the printer""s components by refusing to operate when the detection system is unable to recognize the particular type of media that is loaded in the printer.
In the field of printer technology, numerous methods have been developed for applying ink to paper, cards or other print media in a controlled manner. One of the most common methods is using ink ribbons. A flexible ribbon substrate is impregnated or coated with ink that adheres to a paper or plastic card upon application.
Although xe2x80x9cinkxe2x80x9d is the term commonly used to describe this technology, the substance used for printing is typically not xe2x80x9cinkxe2x80x9d in the popular sense of the word. Porous ribbons, e.g., cloth, are usually impregnated with a dark powder which has enough liquid or gel content to promote its binding characteristics. Non-porous ribbons are typically coated on one side with a dry paste-like substance. In either case, the substance is usually referred to as xe2x80x9cink,xe2x80x9d and the ribbons as xe2x80x9cink ribbons.xe2x80x9d This terminology is common in the industry and is used in the following descriptions. The termxe2x80x9cribbonxe2x80x9d as used herein is meant to encompass any type of printer technology that employs a flat, linear material wound around a spool.
At the time of printing, the back side of the ribbon is hit by one or more xe2x80x9chammers,xe2x80x9d which drive the front side of the ribbon against a paper or plastic card being printed on. The pressure and/or temperature of these hammers transfers some of the ink deposits from the ribbon to the paper""s or card""s surface in the shape of the hammer""s impact surface. The surface of the hammer may be in the shape of a particular character, e.g., the letter xe2x80x9cA,xe2x80x9d or a single dot which is combined with other dots to form a character. In either case, the method of transferring ink from a ribbon to the paper or the card is the same.
Since printer ribbons must be replaced periodically, most printers use spools designed to be replaced by an operator. Spools are also called xe2x80x9ccores,xe2x80x9d and ribbon/spool combinations are usually sold as a single item.
Typically a spool is mounted on a spindle for operation, the spindle being generally cylindrical in shape and attached to a motor-operated assembly that controls the rotation of the spool. In most cases, only the take-up spool is controlled, while the supply spool is allowed to rotate freely as ribbon is removed from it by the force exerted on the ribbon by rotation of the take-up spool.
Removing the used spool from the spindle should be easy, fast and be done without tools by a non-technical person with little or no instruction.
In addition to standard ink ribbons and hammers, other printer technologies have also been developed. For example, thermal transfer, hot transfer, and die sublimation transfer. Although these technologies differ from each other in significant ways, they have two things in common. First they typically involve a controlled transfer of the print substance from a substrate onto a print medium, and second, the act of printing depletes the print substance so that the substrate must periodically be replaced.
The use of replaceable ribbons, supply spools, and take-up spools is therefore common in many different types of printers.
Ribbon Identification Art
Several different types of ribbon can be used in a printer, such as monochromatic ribbons, colored ribbons, holograms, or overlays.
Each type of ribbon has several parameters that a printer needs to be adjusted to accommodate. For example, contrast/intensity, speed, offset, temperature, synchronization, and/or number of printing jobs available.
Having an operator manage the changing of parameters each time a new ribbon type is inserted into a printer creates a likelihood that the operator may make a mistake, thereby damaging the printer. Therefore, several kinds of ribbon identification devices have been developed.
Some prior art ribbons were detected through the use of magnets or by creating ribbon strips that have markings along the strip that can be detected. The problem with these prior art solutions are that the ribbon strips with markings require a complicated detection process for deciphering the code on the ribbon and much of the ribbon is wasted on the markings. Further, the magnets can be difficult to replace and are yet another tangible piece of the printer that need to be produced and later maintained.
Another prior art detection process is by attaching an identification device to the ribbon spool. The problem with this mode of detection is that any user could remove the attachment and put on a different one thus eliminating the benefit of having a detection process identify the type of ribbon used to set the parameters within the printer.
Optical Color Coded Art
A common ribbon identification device has a white LED (light emitting diode) and a photo-transistor positioned on the printer. The ribbon identification device can be considered according to three stages of development.
First, a pattern of marks, either mark being white or black, is applied on the customer side 62 of the core. See FIG. 1. The white mark reflects the highest light intensity produced by the white LED onto the photo-transistor, whereas the black mark reflects the lowest intensity as it absorbs the visible wavelengths. Considering the output voltage of the photo-transistor is directly proportional to the light intensity it receives, it is possible to set an identification system for two ribbons, one identification system having a white identifier and one having a black identifier. Depending upon the photo transistor, the output voltage is relative to the light intensity. A white mark may have an output voltage of 0 Volts, a black mark may have an output voltage of 5 Volts, therefore a 50% black gray mark may have an intensity of 2.5 Volts.
Second, an extension of the basic process described above consists of detecting various light intensities using a gray scale. A 100% black mark reflects the minimum light intensity and a 0% black mark is considered as a white mark and reflects the maximum light intensity. Therefore, a 50% black mark, or gray mark, reflects half of the intensity of a white mark.
The gray scale can then be extended according to the sensing element""s receptiveness. For example, the sensing element may detect changes in increments of every 5% black or every 10% black.
This identification system is applicable for several different ribbons, one being a particular percentage of black xe2x80x9cgrayxe2x80x9d per type of ribbon.
The number of identifiers needed depends on the scale of gray that the photo-transistor can identify.
The gray scale could be replaced by a color scale. The process is identical because each color has an equivalent light luminosity in the gray scale.
Third, it is possible to increase the number of identifiers by combining several gray scales in a band placed onto one ribbon. Each zone needs to have a different gray scale than the one before and the one after it. For example, if there are three zones, Zone 1, Zone 2 and Zone 3, any of the three zones can be filled with three different gray scales such as: gray 20%, gray 40%, gray 60%. Then, Zone 1 has 3 distinct grays available, Zone 2 has 2 distinct grays available, and Zone 3 has 2 distinct grays available.
In this example, if you multiply the possible number of colors available to fill each zone (3xc3x972xc3x972=12) you get 12 combinations used as identifiers.
In another configuration, if we consider a band made of five zones, each one of them is filled with any of four different colors, then there are (4xc3x973xc3x973xc3x973xc3x973=324) 324 identifiers available.
The problems with this technology are due to the detection criteria of light intensity and the loss of ribbon, the ribbon core must complete a full rotation before the ribbon identifiers have been detected. The ribbon loss in the prior art is further due to the fact that the identifier is not repeated over the entire circumference of the core. Thus, the ribbon core must be rotates one entire revolution in order for the sensor to read the entire identifier from the starting point to the end point.
The present invention overcomes the problems inherent in the prior art. The only identification criteria of light intensity in the prior art can be disrupt by any parasitic light source from inside or outside the mechanism at any time of the process.
The preceding and other shortcomings of the prior art are addressed and overcome by various aspects of the present invention.
To resolve the problems inherent in the prior art, a color sensor solution that is capable of detecting multiple colors for an unlimited number of combinations with quickness, precision and no ambiguity, that does not suffer from parasitic luminous sources and from loss of ribbon during the detection process is needed.
The present invention relates to a ribbon identifier that detects a color coded band comprising multiple colored zones positioned on a ribbon core that fits in a printer. Each type of ribbon is associated with a specific and unique color coded band. The band may also be partly visible to the operator when loading the ribbon. When the color coded band is detected, the control program of the printer sets the parameters associated with that color coded band, ensuring proper printing.
The foregoing and additional features and advantages of the present invention will become apparent by way of non-limitative examples shown in accompanying drawings and the detailed description that follows. In the figures and written description, numerals indicate the various features of the invention, like numerals referring to like features throughout both the drawings and the written description.